Trinity Mirror boss Sly Bailey tore into the legacy of previous chief executive Philip Graf, attacking the former management for letting the group's national newspapers "drift".

She said the Mirror, Sunday Mirror, People and the group's Scottish titles should have been given stronger direction from executives who were "systematically risk-averse".

"The national titles drifted," she said. "It's clear now that these great brands could have benefited from clearer direction and control from the centre. Suffice it to say, I would have done it differently."

Ms Bailey said new ideas were allowed to "wither on the vine" and the approach to structured thinking was "weaker than I had experienced elsewhere".

"No real effort has been put into areas where scale and our own multiple businesses can be a real advantage."

Ms Bailey took over in February and soon assumed direct control of the group's newspapers, overseeing the Mirror's shift away from the "serious" news agenda adopted by the editor, Piers Morgan.

Today she announced the findings of her strategic review, vowing to slash costs without resorting to the sale of any major titles.

The Trinity chairman, Victor Blank, defended his board's handling of the company before the arrival of Ms Bailey, the former IPC Media chief.

"The board's job is to ensure there's a good executive team running the company efficiently - the board did its job," he said.

"Sly described pretty accurately the situation that obtained. Change was not being executed fast enough."

Ms Bailey berated the previous management for allowing the group's Sunday and Scottish newspapers to eat into each other's market share.

"It was simply unacceptable that the Daily Mirror and Daily Record compete against each other [in Scotland]," she said.

"They were knocking the hell out of each other both in terms of positioning and price, destroying value and leaving a clear run for a key competitor."

On Sundays, when readers often make multiple purchases, few people were buying both the Sunday Mirror and the People, she said.

"If people are buying two newspapers let them buy both of ours rather than one of ours and one of somebody else's."

She said there were benefits to be gained from the "scale and variety of our publishing assets" but warned against standardising content by pooling editorial.

Ms Bailey confirmed some of the 550 jobs to be cut at Trinity Mirror will be editorial.

The group would prefer people to leave voluntarily rather than through forced redundancies, she said, insisting there was no "ageist policy" designed to offload older staff.

She insisted there were no plans to remove Morgan now the circulation of the flagship Daily Mirror has dipped below 2 million copies.

"I'm confident we have a highly talented editor," she said. "But I don't think guidance has been provided in terms of the direction of the business in the past.

"My relationship with Piers is very important to the success of the newspaper going forward."

Asked if Morgan's job was safe, she replied: "I don't think I could say my job is safe. No one ever knows if their job is safe. We have no plans to change the editor of the Daily Mirror."

She said the 2 million circulation figure was not a "magic number" that particularly interested her.

"There has not been a threshold below which the Daily Mirror is no longer effective for advertisers.

"Am I happy it fell below 2 million? No, of course not... But there are many measures of brand health."

Shares in Trinity Mirror lifted 8.5p to hit 481p at lunchtime.

The group reported half year pre-tax profits of £80.4m, up from £78.4m last year.

It also announced it was disposing of its nine titles in Northern Ireland, part of its 260-strong regional stable.